CN1639364A

CN1639364A - Metal foam casting apparatus and method

Info

Publication number: CN1639364A
Application number: CNA038049791A
Authority: CN
Inventors: 斯科特·尼科尔
Original assignee: Cymat Corp
Current assignee: Cymat Corp
Priority date: 2002-02-01
Filing date: 2003-01-31
Publication date: 2005-07-13
Also published as: US6998535B2; CA2474949A1; DE60301947D1; WO2003064711A1; EP1470262B1; KR20040075964A; MXPA04007455A; US20050161188A1; DE60301947T2; EP1470262A1; BR0307407A; JP2005515902A; ATE307218T1

Abstract

A method for casting articles from metal foam includes a molten metal bath and a foam forming means. The foam is drawn into a ladle, within a heated chamber, which transports a foam sample to a mould. The ladle deposits the foam sample into the mould and the mould is closed. Once cooled and hardened, the formed article is removed. The system of the invention comprises a molten metal bath, a heated foam collecting chamber, a ladle for drawing a sample of the foam and for transporting the sample to a mould. The present invention provides an apparatus for carrying out the method.

Description

Casting metals foamy Apparatus and method for

Technical field

The present invention relates to casting metals foamy Apparatus and method for.

Background technology

In the production of products such as for example automobile, more and more need be by the assembly of the material produce of the ratio of high strength/weight.In order to meet this requirement, it is relatively light and the bigger material of intensity is made these assemblies that people seek weight emphatically.A kind of material that has been proposed use is a foamed metal.

Metal foam generally obtains to form the melt metal foam by import gas in the melt metal pond.Then, extraction and cooling foam.Replace standard metal with metal foam, have many advantages, for example satisfy high strength/weight ratio above-mentioned, high vibration-or shock absorption quality and sound-absorbing quality.Prior art has instructed the whole bag of tricks pan in next life to belong to foam, and for example the patent No. is to mention in 5221324 and 5622542 the United States Patent (USP).The method of above-mentioned generation gas has following several: (1) uses a kind of air feeder, and it can be blown into or be injected into gas in the molten metal; (2) using gas propellant or pore forming material, when heating, they discharge gas; (3) use impeller, desired gas is introduced in the pool of molten metal.Also known in the prior art, can in molten metal, add multiple auxiliary agent and help the integrity that foam keeps formed hole.

Though the method that the method that provides many productions can cut into the metal foam sheets of desired size in the prior art, provide foam is made have more complicated 3 dimensional coil geometry seldom.The US5865237 United States Patent (USP) provides a kind of like this method.In this piece document, mention, place the heating chamber internal heating to produce metal foam metal-powder and the pore forming material that can discharge gas.After foam generates, molten mixture is injected in the mold cavity.Then, mixture can continue to bubble in mould, to guarantee that foam can fill up the entire die cavity.

There are many weak points in the method for mentioning in the prior art.At first, method must be that intermittent type is implemented.That is to say that the production of an assembly may further comprise the steps: required powder is joined in the heating chamber, melting powder, material injected mould, last, finish foaming process, cooling die and take out end article.Therefore, the method for mentioning in No. 5865237 patents of US is very consuming time.And, in the thing that will foam is injected into process in the mould, need to provide a power to be applied on the foam hole.This power will inevitably be destroyed some holes, thereby reduce the advantage of this foam materials.In addition, this patent requires to use piston that foam material is injected mould.Because the piston in ' No. 237 patents is with metal, and it is in all the time and keeps in the pyritous heating chamber that metal is in molten state, so piston is easy to be stuck by high-temperature damage.And the transfer of foam material must be carried out in the specific time in this process, to guarantee to shift the generation of post-foaming.At last, ' instruction of No. 237 patents is pressed into foam material the method described material of weight feed accurately in the mould.Therefore, the size of end article and density are inconsistent.

The invention provides a kind of metal foam casting equipment and method, described equipment and method can be eliminated at least some weak points of the prior art.

Summary of the invention

In one embodiment, the equipment with the metal foam casted article provided by the invention comprises:

A pool of molten metal;

A metal foam producer that is arranged in pool of molten metal;

A heating chamber that links to each other with pool of molten metal by conduit;

A ladle that places heating chamber, is used to receive foam sample;

A device that is used for taking out ladle from heating chamber; And,

A mould that has with article shape complementary die cavity.

A device that is used for taking out ladle from heating chamber; And,

A mould that has with article shape complementary die cavity.

In another embodiment, the method for use metal foam casted article provided by the invention comprises:

-metal of molten is provided;

-make molten metal produce foam;

-extraction foam sample;

-shift sample to mould;

-cooling die; And

-taking-up formed article.

Description of drawings

Above-mentioned and other features in the preferred embodiment for the present invention are more obviously embodied in the detailed Description Of The Invention in conjunction with the accompanying drawings below, wherein:

Fig. 1 is the sectional view according to the casting equipment that is in foaming stages of an embodiment of invention.

Fig. 2 is after taking out foam sample, the sectional view of casting equipment.

Fig. 3 is in the mould of open mode and the sectional view of foam transfer vessel.

Figure 4 and 5 are the sectional views that are in the mould in two stages removing container.

Fig. 6 is the sectional view of the mould that is in the close position.

Fig. 7 A and 7B are respectively top cross-sectional view and the side sectional views before the foam article unmodified.

Fig. 8 is the sectional view of trim press.

Fig. 9 A and 9B are respectively the top cross-sectional view and the side sectional views of the foam article after modifying.

Embodiment

Fig. 1 has represented an embodiment of present device.This equipment comprises a heating chamber 10, and it links to each other with the pool of molten metal 12 that molten metal 14 is housed.Using any known heating installation that pool of molten metal 12 is maintained enough temperature makes metal be in molten state.Gas inlet or injection port 16 are located at the bottom of pool of molten metal 12, by its suction gas 13.Gas 13 bubbles in molten metal 14, thereby makes molten metal 14 form foam 18.Gas inlet 16 comprises a permeable porous nozzle of gas.Perhaps, inlet can comprise that any gas that can make is in blistered known structure when the molten metal.Can know that from prior art the gas bubbles of rise makes the upper surface of molten metal 14 form foam 18.

One preferred embodiment in, pool of molten metal 12 is divided into two parts by a divider wall 20, thereby forms a foam generating portion 22 in this pond.As shown in the figure, gas inlet 16 is preferably placed at the below that foam forms part 22, thereby forms foam formation foam 18 in the part 22 at foam.Be appreciated that the vertical uplift owing to bubble 13, foam will preferentially form in the part 22 at foam and form.In order to ensure this point, divider wall 20 partly is immersed in the molten metal 14.

Divider wall 20 comprises the diverter 24 of a bending, and it is the example that the foam 18 that is used for rising imports the device of heating chambers 10.In heating chamber 10, be provided with a foam transfer vessel or ladle 26.Ladle 26 links to each other with reciprocating bar 28, and it can laterally move ladle in heating chamber 10.The device of other any removable ladle 26 all may be utilized.As shown in Figure 1, ladle 26 at first is placed in the position near the sidewall of pool of molten metal 12.And ladle 26 is in and places in the heating chamber 10, and the opening 30 of ladle 26 and the sidewall of pool of molten metal 12 are on the same horizontal plane.The purpose that adopts vertically orient is to make the foam 18 of foam diverter 24 guiding enter and fill up ladle 26.As long as can make foam 18 be full of ladle 26, ladle 26 takes other any orientation all to be fine.For example, in another embodiment, ladle can be placed in the top slightly of pool of molten metal 12.Perhaps, can use other steering gear to make foam fill up ladle 26.In another embodiment, foam 18 can be scooped into or place ladle with other mode.Diverter 24 can be adopted Any shape or direction, as long as can reach aforementioned purpose.

In case ladle 26 has filled up foam sample 27, bar 28 just is retracted, thereby ladle is withdrawed from from heating chamber 10.Fig. 2 represents the equipment that has the ladle 26 that is retracted of the present invention.As shown in the figure, be provided with a closable opening 34 with pool of molten metal 12 sidewalls 32 relative, heating chamber 10, ladle 26 can be from wherein passing through.As shown in Figure 1, opening 34 preferably is in closing condition, when ladle 26 will pass through (as shown in Figure 2).Can reduce the calorific loss of heating chamber like this.But opening 34 also can be in opened condition and adopt alternate manner to keep temperature in the heating chamber 10.And, as shown in Figure 2, determine that the size of opening 34 reduces the gap of ladle 26.Like this, when regaining ladle 26, the upper end 31 of opening can be wiped the foam of opening 30 height that exceed ladle off.Like this, the volume of the foam sample of regaining by ladle 26 27 can remain unanimity.And, strike off step rather than foam is pressed in the ladle by employing, can keep forming the integrity in foamy hole.

Keeping heating chamber 10, to be in heated condition be can not cool off and solidify up to shaping stage in order to ensure foam 18 to finish (below will further narrate).In a preferred implementation, heating chamber 10 maintains about 500-700 ℃.

Fig. 2 has also represented to be equipped with the molten metal and the foamy pond 36 of overflowing from pool of molten metal 12, it collects molten metal and foam in the bottom of heating chamber 10.These overspills will be recycled in the pool of molten metal 12.

Fig. 3 has represented to be regained fully from heating chamber 10, and places the mould 39 intermediary ladles of dimidiation.Mould 39 comprises first half 38 and second half 40.Each half point of mould is not provided with

cavity

42 and 44, and both meet the outer shape of the goods of formation in conjunction with formed

cavity.Cavity

42 and 44 is equipped with the breach 45 of a part.When the combination of two portions mould, two breach 45 are in conjunction with forming the overflow space around goods.This will be further described below.

As shown in Figure 3, in case ladle is between two portions of mould, the content of ladle must be introduced in the cavity of mould.Two portions of mould preferably are in the above and below of ladle, so only need the content of ladle is poured in the mould cavity that is in the below.

Fig. 3 to Fig. 5 represents a preferred implementation of ladle 26, and ladle 26 is designed to be convenient to foam sample 27 is poured in the die cavity.In this embodiment, ladle has four parts, and

piece

46 and 48 has formed the end, and

piece

50 and 52 has formed the side.As shown in Figure 3, when coupling together,

piece

46,48,50 and 52 just formed complete ladle.In the time will pouring into foam sample 27 in the mold cavity, the ladle 26 split distinct portions that are split into.In one embodiment, as shown in Figure 4 and Figure 5, split process at first is to take two of bottoms apart by drawing

back piece

46 and 48, uses two 50 of similar methods separate sides and 52 subsequently.At first removing two of bottoms is to inject mold cavity in order to ensure foam sample 27 with the size of expection.

Fig. 6 has represented to be in the mould 39 of closure state, and foam sample 27 is housed in its die cavity.As figure, when mould 39 is in closure state, the breach 45 that the front was described just combines and has formed an overflow space 54, exceeds the unnecessary foam inflow of mold cavity volumetrical herein.After the mold cools down, take out the metal foam goods that are shaped.

In preferred embodiment, as is known in the art, mould 39 is made by sand.Make mould with sand and have many good qualities, comprise that the cost of manufacture of raw materials cost and mould is low and conduct heat seldom.About after a bit, as poor conductor of heat, sand can make the foam in the mould keep temperature near melted state.But, steel die can the replace sand molding jig.By prior art as can be known, in order to prevent that foam from cooling off too early, hardening, heat steel die.For example, in the US5865237 United States Patent (USP), told about the method for using steel die.

The process foam sample 27 is transferred to closed mould from heating chamber in, foam should be remained under the melt temperature, thereby make foam be in the molten state of easy shaping.One preferred embodiment in, by quick transfer foam sample to mould and finish casting cycle and prevent molten foam cooling.Quick transfer has like this avoided carrying out the needs of indirect heating.And, because mould preferably made by the sand that combines by water, so indirect heating causes moisture evaporation and mould to be disintegrated.In another embodiment, the ladle zone of moving adopts the mode similar with heating chamber 10 to heat to prevent that foam sample from cooling off.In this case, if use husky molding jig, mould itself is not heated for above-mentioned reasons.In addition, if use metal die, can be heated to the whole zone and the mould itself of ladle process temperature required.In the case, the closed postcooling of mould makes the casting foam curing.

Fig. 7 A and B represent the vertical view and the side-view of the foam article 58 that takes out respectively from mould shown in Figure 6.As shown in the figure, goods 58 have comprised ring 60, and this ring is formed by the residue foam in the overflow space 54.

Fig. 8 represents to modify or clamping pressure machine 62, is used to remove the ring 60 on the molded article.Pressing machine 62 comprises a base 64 of holding goods 58, and it has first blade 66.Goods place on the base 64, and ring 60 is leaned against on first blade 66.Pressing machine also comprises a crimping section 68, and it has second blade, 70, the second blades 70 and forms a pliers with first blade 66.Base 64 and crimping section 68 all are provided with a cavity that is used for holding goods 58 between their blade.When operation, as previously described, goods 58 place on the base 64.Then, crimping section 68 is shifted to base 64, makes two blade contacts.Like this, under the common shearing action of blade 66 and 70, the ring 60 on the goods 58 is fallen by folder or modifies.

Goods after Fig. 9 A and B represent to modify.

In above description, foaming method is to use a gas supply port that is in the pool of molten metal.But, also can adopt other any foaming method.For example, instruct, in molten metal, use whipping agent to replace gas supply device and produce metal foam as No. 5865237 United States Patent (USP)s of US and other bibliography.In addition, molten metal can add and variously knownly can stablize the formed foamy auxiliary agent of molten metal.In another embodiment, in pool of molten metal 12 impeller is housed, it is introduced air in the molten metal.In other embodiments, gas inlet 16 of the present invention comprises a rotary blade or a vibrating nozzle.

Those skilled in the art will appreciate that by the present invention the metal foam of available various density is made goods.Foamy density (it is to form the size in foamy hole and the function of wall thickness) depends on various factors, and the introducing speed of gas for example joins the value volume and range of product of the foaming foam auxiliary agent in the molten metal.

Another embodiment of mould of the present invention shown in Figure 10 and 11, wherein with the figure of front in components identical use identical Reference numeral to represent.In this embodiment, mould is generally represented with 74.Mould 74 comprises a die region consistent with the end article shape 76 and funnel area or rising head 80.Funnel area 80 guiding foams 27 leave ladle 26.As described above, ladle 26 preferably is made up of four parts, i.e.

sidewall

50 and 52 and the

piece

46 and 48 that forms the bottom.In Figure 10, the

piece

46 and 48 of bottom is in separate stage, makes foam 27 can fall into mould.In this process, the inwall 82 of the funnel area 80 of mould 74 imports die region 76 with foam.Mould 74 can be made by steel, pottery, graphite, sand or other material.

In one embodiment, can use piston (not marking) that foam 27 is pressed into die region 76.This piston meets the size of funnel area 80.Piston can be made by the infusible material.Perhaps, by swing die 74 foam 27 is pushed die region 76.In another embodiment, produce vacuum, foam is pressed into die region by applying air pressure or rotating mold.To one skilled in the art, other variety of way is conspicuous.

Figure 11 represents that foam transfers to the later mould 74 of die region 76.Do not show ladle in the drawings.

Can understand, not need the mould in closed this embodiment to form end article.But mould is separable, thereby can take out the goods of moulding.Should understand, in order to describe the feature of mould, the ratio of funnel area is exaggerated, and substantial proportion and size depend on formed end article, and is determined by those skilled in the art easily.

Figure 12 is illustrated in the goods 84 that form in the mould of Figure 10 and 11.As shown in the figure, the part 86 of molded article 84 is mated with the bottom of the funnel area 80 of mould 74.As mentioned above, the described part 86 of goods is easy to modify by cutting or other method, thus the end article that obtains expecting 87, and its outer shape is consistent with the shape of die region or cavity 76.Similarly, in order to illustrate this embodiment, the ratio of modifying part 86 is exaggerated.

Refer again to Figure 10, the die region 76 of mould 74 is provided with a collection not outlet or the hole 88 of blistered liquid metal.Figure 11 represents to collect the hole 88 of liquid not sparkle metal.Figure 12 represents a solid metal block 90, and it is corresponding to the molten metal that is collected in the hole 88.Be appreciated that this extra section 90 is easy to excise from the end article of expectation.

After Figure 13 represents to form the expectation goods, be in the mould 92 of open mode.This mould comprises metal founding 94, has filled sand 96 in its inside.Mould inside has a former 98 that is formed by sand.The upper end of mould is provided with a funnel area described above or guide groove, but not shown in Figure 13.There is a hole 100 described above the lower end of mould.As shown in the figure, the shape in hole is a dove tail shape.

Figure 14 is illustrated in the goods 102 in the mould that is formed at Fig. 3 before the modification.As shown in the figure, goods 102 comprise first end 104, and it is corresponding to the shape of funnel (aforementioned) part.Second end 106 is corresponding to the liquid metal that enters hole 100.

Figure 15 represents to modify the goods shown in Figure 14 102 behind first terminal and second end.

The invention provides a kind of casting process, it does not resemble and requires to interrupt foam the prior art and produce step.Like this, the present invention considers that a successive produces foam process, and the part foam can be removed and cast in the mould.In another embodiment, this equipment can be provided with a plurality of ladles, and each ladle takes out sample in successive the time from same heating chamber.These ladles are placed on sample separately in the different moulds then.Like this, invention provides a kind of continuation method of casting metals foam article.

In preferred embodiment, metal is an aluminium.But, also can use other any metal in the present invention.

Although invention has been described by means of specific embodiment, for those skilled in the art, the various changes that do not deviate from described design of the present invention of accompanying Claim book and scope all are conspicuous.Although invention has been described by means of specific embodiment, for those skilled in the art, the various changes that do not deviate from described design of the present invention of accompanying Claim book and scope all are conspicuous.

Claims

1. equipment with the metal foam casted article, it comprises:

A pool of molten metal;

Metal foam producer in pool of molten metal;

A ladle that in heating chamber, is used to receive foam sample;

A device of from heating chamber, regaining ladle;

A mould that has with article shape complementary die cavity.

2. equipment as claimed in claim 1, wherein said heating chamber is heated, and makes foam keep molten state.

3. equipment as claimed in claim 1, wherein said metal is an aluminium, and heating chamber maintains about 500-700 ℃.

4. equipment as claimed in claim 1, wherein heating chamber comprises an opening that passes through when allowing ladle turnover heating chamber.

5. equipment as claimed in claim 1, it also comprises the measuring apparatus of the foam sample that obtains pre-determined volume.

6. equipment as claimed in claim 1, wherein frothing machine comprises a gas inlet.

7. equipment as claimed in claim 6, wherein frothing machine comprises a nozzle that link to each other with source of the gas, that gas can pass.

8. equipment as claimed in claim 6, wherein frothing machine comprises a rotary blade, this impeller has and is used for discharging gas, making the blistered outlet of molten metal to molten metal from source of the gas.

9. equipment as claimed in claim 1, wherein frothing machine comprises the heat activated chemical foaming agent that is dissolved in the molten metal.

10. equipment as claimed in claim 1, wherein frothing machine comprises air is introduced rotary blade in the molten metal.

11. equipment as claimed in claim 1, it also comprises the unnecessary foamy modification device of removing on the goods.

12. equipment as claimed in claim 1, it also comprises transfers to transfer device in the ladle with foam.

13. the method with the metal foam casted article, it comprises:

-molten metal is provided;

-make molten metal produce foam;

-taking-up foam sample;

-with sample transfer to mould;

-cooling die; And,

-taking-up formed article.

14. method as claimed in claim 13 is wherein taken out foam sample with ladle.

15. method as claimed in claim 13, wherein sample has predetermined volume.

16. method as claimed in claim 15 is wherein by measuring the sample foams that the foamy amount that shifts in the reverse mould tool obtains pre-determined volume.

17. method as claimed in claim 13, it also comprises modifies formed article to remove unnecessary material.